The following processes are known as methods for production of 1,3,3,3-tetrafluoropropene that is one kind of fluoroolefin.
For example, Non-Patent Document 1 discloses a process of dehydroiodination of 1,3,3,3-tetrafluoro-1-iodopropane with alcoholic potassium hydroxide.
Patent Document 1 discloses a process of production of 1,3,3,3-tetrafluoropropene by reaction of 1-chloro-3,3,3-trifluoropropene (CF3CH═CHCl) with hydrogen fluoride in the presence of a fluorination catalyst, wherein the fluorination catalyst is an activated carbon supporting thereon an oxide, a fluoride, a chloride, a fluorochloride, an oxyfluoride, an oxychloride or an oxyfluorochloride of one kind of metal, or two or more kinds of metals, selected from the group consisting of chromium, titanium, aluminum, manganese, nickel and cobalt.
Patent Document 2 discloses a process of production of 1,3,3,3-tetrafluoropropene by reaction of 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of a fluorination catalyst, wherein at least either one of titanium and chromium is used as the fluorination catalyst.
Non-Patent Document 2 discloses a process of dehydrofluorination of 1,1,1,3,3-pentafluoropropane with potassium hydroxide.
Patent Document 3 discloses a process of producing 1,3,3,3-tetrafluoropropene continuously from 1,1,1,3,3-pentafluoropropane by passing the 1,1,1,3,3-pentafluoropropane through a reaction region of carbon material or metal-compound-supported carbon material at an elevated temperature in a gas phase.
Patent Document 4 discloses a process of production of 1,3,3,3-tetrafluoropropene, including: a first step of forming 1-chloro-3,3,3-trifluoropropene by reaction of 1,1,1,3,3-pentachloropropane with hydrogen fluoride; and a second step of reacting the 1-chloro-3,3,3-trifluoropropene obtained in the first step with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst.
Patent Document 5 discloses a process of production of 1,3,3,3-tetrafluoropropene by dehydrofluorination of gaseous 1,1,1,2,3,3-hexafluoropropane by contact with an activated carbon, and then, dehydrofluorination of the resulting gaseous 1,1,1,2,3-pentafluoropropane by contact with a metal-salt-doped activated carbon.
In the production of 1,3,3,3-tetrafluoropropene, the product of the reaction process generally contains not only the 1,3,3,3-tetrafluoropropene and the impurities such as the raw material compound and by-products but also the acidic component as mentioned above. Thus, there is a need to perform an acid removal process so as to remove the acidic component by washing operation, i.e., washing the reaction product with water or aqueous basic solution. When the reaction product contains hydrofluoric acid, it is desirable to bring the reaction product into contact with concentrated sulfuric acid etc. and absorb the hydrofluoric acid by the concentrated sulfuric acid etc.
It is also common practice, in the production of 1,3,3,3-tetrafluoropropene, to continuously perform a distillation process on the 1,3,3,3-tetrafluoropropene containing the impurities such as the unreacted raw material, by-products and entrained water after the acid removal process (hereinafter sometimes referred to as “crude 1,3,3,3-tetrafluoropropene”) so as to remove the impurities and purify the 1,3,3,3-tetrafluoropropene.
When the crude 1,3,3,3-tetrafluoropropene contains water, the distillation process faces the problems that: the impurities are difficult to remove; and the water remains in the 1,3,3,3-tetrafluoropropene by the formation of an azeotropic mixture of the 1,3,3,3-tetrafluoropropene and water. For stable, continuous distillation operation, the crude 1,3,3,3-tetrafluoropropene containing the impurities such as the unreacted raw material, by-products etc. needs to be dehydrated sufficiently and then fed continuously to distillation equipment such as a distillation column. It is thus preferable to perform a dehydration process after the acid removal process and before the distillation process, that is, between the acid removal process and the distillation process. It is also preferable, in a plant as an industrial facility for commercial production of 1,3,3,3-tetrafluoropropene, to adopt a simple and efficient dehydration process that does not require large-scale equipment. For example, one conceivable way is to perform a dehydration process and, after the dehydration process, temporarily store in a tank the crude 1,3,3,3-tetrafluoropropene that does not at least contain water but contains the other impurities such as the unreacted raw material and by-products so that the 1,3,3,3-tetrafluoropropene can be fed stably to the subsequent distillation equipment for stable plant operation.
Patent Document 6 discloses, in the production of the 1,3,3,3-tetrafluoropropene, a process of dehydration of 1,3,3,3-tetrafluoropropene containing water after washing with water or aqueous basic solution by contact with a specific kind of zeolite.
Patent Document 7 discloses, in the production of 1,1,1,3,3-pentafluoropropane, a process of dehydration of the 1,1,1,3,3-pentafluoropropane containing water after washing with water or aqueous basic solution by contact with a specific kind of zeolite.